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采用Ｌ－~３Ｈ精氨酸转化法实验，建立了一氧化氮合成酶（ＮＯＳ）测定法，并对大鼠和牛脑组织ＮＯＳ的生化特性以及大鼠脑组织ＮＯＳ的分布进行研究。结果表明：大鼠和牛小脑提取液ＮＯＳ酶活性存在时间和剂量依赖性，大鼠小脑ＮＯＳ底物Ｌ－Ａｒｇ的Ｋｍ值为１．６μｍｏｌ／Ｌ，Ｖｍａｘ为２３．９ｐｍｏｌ·ｍｇ~（－１），ｍｉｎ~（－１）；大鼠小脑ＮＯＳ依赖于Ｃａ~（２＋）、钙调蛋白（ＣａＭ）、尼克酰胺脱氢酶Ⅱ（ＮＡＤＰＨ）和四氢生物喋呤（ＢＨ＿４），其ＥＣ＿（５０）分别为０．５５ｍｍｏｌ／Ｌ、３３ｎｍｏｌ／Ｌ、３２．５μｍｏｌ／ Ｌ、０．４３μｍｏｌ／Ｌ。３ｍｍｏｌ／ＬＥＧＴＡ可以完全抑制大鼠小脑提取液ＮＯＳ活性；１ｍｍｏｌ／ＬＣａＭ拮抗剂三氟啦嗪（ＴＦＰ）能完全抑制ＮＯＳ活性，其ＩＣ＿（５０）为１．７２μｍｏｌ／Ｌ；ＮＯＳ抑制剂ＮＧ－甲基－Ｌ－精氨酸（Ｌ－ＮＭＡ）能够竞争性抑制ＮＯＳ活性，其ＩＣ＿（５０）为１．５６μｍｏｌ／Ｌ。对与ＮＯＳ具有同源性尼克酰胺脱氢酶Ⅱ黄递酶（ＮＡＤＰＨ－ｄ）活性进行研究，发现ＮＯＳ仅是ＮＡＤＰＨ－ｄ活性的一部分。大鼠神经组织中小脑ＮＯＳ活性最高，其次为嗅球、下丘脑和纹状体，而脊髓最低；大鼠神经组织?
L-3H-arginine conversion assay was used to establish a method for the determination of nitric oxide synthase (NOS). The biochemical characteristics of NOS in rat and bovine brain and the distribution of NOS in rat brain were also studied. The results showed that there was a time-and dose-dependent manner in the activity of NOS in rat and cerebellar extracts. The Km value of L-Arg in rat cerebellum was 1.6μmol / L and Vmax was 23.9pmol · mg ~ (-1) , Min ~ (-1). The content of NOS in rat cerebellum was dependent on Ca 2+, CaM, NADPH and BH 4, ) Were 0.55mmol / L, 33nmol / L, 32.5μmol / L, 0.43μmol / L respectively. 3mmol / LEGTA can completely inhibit the activity of NOS in rat cerebellar extracts; 1mmol / L LCA antagonist trifluoperazine (TFP) can completely inhibit the activity of NOS with IC 50 of 1.72μmol / L; NOS inhibitor NG- L-Arginine (L-NMA) competitively inhibited NOS activity with an IC 50 of 1.56 μmol / L. Studies on the activity of NADPH-d with homology to NOS revealed that NOS was only part of NADPH-d activity. The activity of NOS in cerebellum of rat nerve tissue was the highest, followed by the olfactory bulb, hypothalamus and striatum, while the spinal cord was the lowest.